GENOTYPE X ENVIRONMENT INTERACTION AND GRAIN YIELD STABILITY OF FINGER MILLET (Eleusine coracana (L) subsp. coracana) VARIETIES IN EASTERN AND WESTERN, ETHIOPIA

Finger millet is adaptability to adverse agro-ecological conditions with low input, tolerant to moisture stress and plays a significant role both as food grain and animal feed in areas where production of other cereals are reduced by marginal environments. The national and regional research centers recommended considerable numbers of varieties to varied agro- ecologies to increase the productivity of finger millet. Hence, it is necessary further evaluation of varieties for stability of yield at varying environments where the varieties were not evaluated. Therefore, this research was conducted to assess genotype by environment interaction and evaluate yield stability of 15 finger millet varieties at six environments of eastern (Mechara, Gelemso, Chelenko and Kuni) and western (Bako and Gute) Ethiopia in 2019. The experiment was laid out in Randomized Complete Block Designs with three replications across all the tested environments. Analysis of variance individual environment showed significant variation among varieties for grain yield at all locations. The mean squares of genotype by environment interaction was significant for days to heading, days to maturity and thousand seed weight, main finger length, neck blast but no significant for other traits. Combined analysis of variance revealed significant differences among varieties, environments and the significant effect of genotype x environment interaction on grain yield. The high significance of GEI indicated that the performances of the varieties were inconsistent across the test environments and the environments had different effects on the yield potential of the varieties. Boneya (4638.98 kg ha-1 ) followed by Bako-09 (4515.28 kg ha-1 ), WAMA (4088.33kg ha-1 ) and Axum (4031.45 kg ha-1 varieties had higher mean grain yield across six locations. AMMI analysis revealed that environment, genotype and GxE interaction had 47.3, 16.97 and 16.2 % contribution to the total sum of squares, respectively, for grain yield. GGE bi-plot analysis identified Bako09 and Boneya were identified as “ideal” varieties with the highest mean grain yield. Stability parameters IPCA1, IPCA2 and AMMI stability value (ASV) from AMMI model, GGE bi-plot and high mean yield, Mecha, Gudetu and WAMA varieties were the most stable( wide adaptation).The GGE bi-plot analysis grouped the six environments into three mega environment and Mechara (E1), Gelemso (E2) and Kuni (E3) were identified as the most discriminating environments. From the present investigation, it can be concluded and recommended that varieties identified as stable and unstable for cultivation over environments could be promoted to wider and specific production in eastern and western Ethiopia.